Sommerville co-founded design agency Attik in Huddersfield in 1986 along with Simon Needham..
The agency quickly established a reputation as a design house which produced striking work and was markedly ambitious in its outlook. In 1995 an office was opened in London although the downturn in 2001 subsequently led to that office being closed.
Over the years, the agency’s client base developed from one largely based on regional clients to an international base comprising brands such as Coca-Cola, Adidas, Sheraton Hotel+Resorts, Camel, Virgin Atlantic, Heineken, Sony, Nike and Baileys.
Attik went on to open offices in London, New York, San Francisco, Sydney and Los Angeles while the original Huddersfield office was relocated to Leeds.
In 2007 Attik was sold to the Japanese advertising conglomerate Dentsu,which styles itself as the world’s largest ad agency brand. Sommerville elected to remain with the new owner in a global creative director capacity.